Pythons have invaded the Everglades, where they flourish in warm, wet habitat that has an abundant buffet of native species to feast on.

The giant snakes were imported to North America as pets, but released or escaped into Florida's wetlands they are proliferating, challenging alligators for the top of the food chain, and potentially positioning themselves to invade much more of the United States.

Conservation biologist Stuart Pimm has dedicated his life to protecting species--but an infestation of 16-foot alien snakes in Florida's iconic Everglades National Park has got him wondering how to eradicate this one. He is worried about the impact on indigenous species--and what could happen if pet owners release other big reptiles into the watery wilderness. (Source: National Geographic)

Continuing their reptile rescue mission in flood-ravaged Thailand, the hunters dig for deadly cobras, wrestle a mammoth crocodile, and head to higher ground hoping to find a Burmese python in its native habitat.